aarondcohen/Set-Functional — pull request #1 by twhaples (2013-02-27 15:50:43+00:00)
Title: Set-Functional should support predicates like is_subset

The following pull request implements the following predicates.
* is_subset
* is_superset
* is_proper_subset
* is_proper_superset

These predicates each operate on two arrayref sets,
and return a value of 0 or 1 (as opposed to '' or 1).

(The packaging metadata has not been changed with this pull request.)